Dye and photographic emulsion containing the same



Patented June 15, 1943 I UNITED STATES PATENT OFFICE DYE AND PHOTOGRAPHIC EMULSION CONTAINING THE SAME Frances Mary Hamer and-Russell James Rathbone, Wealdstone, Harrow, England, assignors to Eastman Kodak Company, Rochester, N. Y. a corporation of New Jersey No Drawing. Application May 22, 1940,

' Serial N0. 336,584 1 In Great Britain May 25, 1939 11 Claims. (01. 260-240) This invention relates to new dyes and interour new dyes from 1:3-thiazine compounds havmediates therefor and to photographic emulsions ing a reactive substituent in the 2 position to the containing such dyes. cyclic nitrogen atom. We have found that in a Certain dyes of the merocyanine class are particularly advantageous method of preparing known to alter. the sensitivity of photographic certain of our new dyes, there may be used 1':3- emulsions. Various dyes of this class have been thiazine compounds having a thio or mercapto described but it has not hitherto been proposed group in the 2 position, and these compounds are to make merocyanine dyes containing a simple ournovelintermediates. Moreparticularlythesub- 1:3-thiazine nucleus. We have nowfound that stituent in the 2 position may be alkylthiol, such these dyes can be obtained by condensing a 1:3- as methylthiol or ethylthiol; arylthiol, such as thiazine compound having a reactive substituent phenylthiol; or aralkylthiol. However, the methin the 2-position to the cyclic nitrogen atom with ods of preparing our new dyes are not limited a compound containing a reactive methylene to those aforesaid since 1:3-thiazine compounds group adjacent to a carbonyl or thio-carbonyl having other substituents in the 2 position may group. be used. For example, compounds in which the It is accordingly an object of our invention to substituent is alkyl, such .as methyl or ethyl;

provide new dyes. A. further object is to proaralkyl, such as w-acetanilidovinyl or w-anilinovide a process for preparing such new dyes. A A-1:3-butadienyl; amino, or the like.

further object is to provide photographic emul- All the above-mentioned intermediates are sions sensitized with our new dyes. A still furpreferably used in the form of their quaternary ther object is to provide new intermediates for salts. We have found that quaternary salts conthe preparation of our new dyes. Yet another taining a simple nuclear substituent such as object is to provide light filters containing our chloro, amino or alkoxy, for example, can be emnew dyes. Other objects will appear hereinafter. ployed as well as the unsubstituted quaternary The .dyes of our invention can, for convensalts. We have found it advantageous to employ ience, be illustrated by the following general the alkhalides, particularly the alkiodides, al-

formula: 7 though other quaternary salts can be employed,

for example, the alkyl sulfates, the alkyl-ptonuenesulfonates, the alkoxyalkyl halides, the

T Q aralkyl halides, or the like. RN H- H)-1=C- =A Such quaternary salts may be condensed with wherein Y represents the non-metallic atoms a compound, which may or may not be cyclic, necessary to complete a 1:3'thiazine nucleus, A containing reafitive methylene group l n represents a divalent non-metallic atom of the to a carbonyl E P t a bo y o poxygen group of elements, such a oxygen or More parti arly such compo nd may b for sulphur, n represents a positive integer, P and example. d m esp clally 3 -s s tuted Q each represent an organic group and P d rhodanines such as 3-ethy1 rhodanme, thiohy- Q together represent the non-metallic atoms necins, such as 1-pheny1-3-ethyl-thiohydan-' essary to complete a cyclic organic nucleus; and wins. barbituric acids. t i c i 2- Rrepresents an alkyl group. 40 thio-2:4-oxazolediones, aroylacetonitriles, cyano- More particularly, P and Q together may repacetamides, such as cyano-acetanilide, benzoylresent the atoms to complete a five-membered t n sac tylacetone. a d the like. or six membered heterocyclic nucleus, such as a In a pref rred method of p p rin certain of nucleus containing sulphur and nitrogen, e. g. 11 new dyes a Compound such as a 2-alky a phodanine nucleus, especially a, {ii-substituted 'thiOl-123-thiiiZiIlB quaternary salt is condensed rhodanine nucleus, or a thiohydantoin nucleus with a compound such as rhodanine in the presor a barbituric acid nucleus or an oxazoledione nce of a strong organic base such as triethy nucleus; alternatively, P may represent cyanogen amme and a suitable solvent such as ethanol. or quinolyl or COR, where R is an alkyl or aryl Other members of our new class of dyes may group, whilst Q may represent acyl or aryl or be prepared by methods analogous to those dis:

alkylamino or arylamino or alkoxyl or carboxyl closed in British Patent Specifications 450,958,

or carbalkoxy 466,097, 470,726, 479,970 and 493,455.

The dyes may, carry simple substituents in the The prep i of our novel intermediates nuclei or in the methenyl chain. may be illustrated by the following examples In accordance t our invention we prepare which are not intended to limit our invention.

EXAMPLE 1.-2-methylthioldihudro-1:3-thiazine I CH: S

3, -S.CHI I 2-thioidihydro-1z3-thiazine (8 g. 1- mol.) was treated with suflicient aqueous sodium hydroxide solution (20%) to dissolve it and then methyl sulphate (1.9 c. c.; 2 mols.) was gradually added, the reaction mixture being kept alkaline by addition of sodium hydroxide solution from time to time. The oil which separated was extracted with ether and the extract was dried with anhydrous sodium sulphate. The base was obtained as a colourless oil, B. P. 155160 C. /50 m. m.

2-thioldihydro-123-thiazine was prepared by converting 3-bromopropylphthalimide into 3- bromopropylamine hydrobromide (see Gabriel & Weiner, Ber. 1888, 21, 2669) andthen treating this with aqueous sodium hydroxide and carbon disulphide.

Z-ethylthioldihydro-i :3-thiazine Reaction between 2-thioldihydro-1:3-thiazine, sodium hydroxide solution and ethyl sulphate was brought about in a manner similar to that above, but completed by heating on the waterbath for half an hour, with occasional shaking.

The twice distilled base was obtained as a colourless oil, 3. P. 145-150/40 m. m.

Ebzsmrrs 2.--2-methylthioldihydro- 1 :3- thiazine methz'odide CHaI The ethiodide was ground with ethyl acetate and dried in a vacuum desiccator, being obtained as a buff powder, M. P. 80-83 C.

2-ethylthioldihydro 1:3 thiazine methiodide resulted by interaction of 2-methyithioldihydro- 1:3-thiazine and ethyl iodide, whereas it might have been expected that 2-methyi-thioidihydro- 1:3-thiazine ethiodide would be obtained.

EXAMPLE 3.-2 methyldihydro 1:3 thiazine methiodide /Cga CH 8 2-methyldihydro-1:3-thiazine (1.8 g.; 1 mol.) was dried by heating in a vacuum on a waterbath. It was corked up with excess of methyl iodide 2.5 c. c.; 2 mols.) and, after some hours, the methiodide separated, sometimes as a cream coloured solid, and sometimes as an oil. It was purified by washing with absolute ether. As it was very hygroscopic, it was kept in a vacuum desiccator before use.

(see Example 2) (5.9 g.) was boiled under reflux with pyridine (20 c. c.) for 20 minutes. The reaction mixture was poured into 100 c. 0. water and the solution concentrated on a steam bath, under reduced pressure, to 30 c. c, and cooled. The crude product obtained was recrystallized from 15 c. c. ethyl alcohol (yield 1.9 g.; 62%). M. P. 88 C. I

EXAMPLE 5.--2-thio-3-methultetrahydro-1:3-thiazine methiodide 2-thio-3-methyltetrahydro-1 3-thiazine (1 g. 1 mol.) and methyl iodide (0.65 c. c.: 1.5 mols.) were sealed in a tube and allowed to stand at room temperature for a few hours. The methiodide which was formed was then ground with ether and obtained as a pure white, deliquescent solid. M. P. 60 0. (yield; 2.05 g.: 99%).

While the process of preparing our new dyes is subject to variation, particularly with respect to the nature and quantity of the quaternary salts employed, the nature and quantity of the compound containing a reactive methylene group employed, the nature and quantity of the basic condensing agent employed, the nature and quantity of the diluent employed, the order of procedure and method of isolation of the dye and the temperature employed, the following examples will serve to illustrate the mode of practising the process oi! our invention. These examples are not intended to limit our invention.

EXAMPLE 6.-3-eth1Jl-5 :Z (3'-ethyldihydro-1 :3 thiazinylidene) rhodanine 2 ethyithioldihydro 1:3 thiazine ethiodide (1.59 g.: 1 moi.), 3-ethyirhodanine (0.81 g.; 1 moi.) triethylamine (2 c. c.:1.5 mols.), and ethyl alcohol (7 c. c.) were heated together on the water-bath, with stirring, for 3 minutes. The resultant solid was washed with water and recrystallized, first from ethyl alcohol, and then from petrol ether, B. P. -1U0. The bright yellow crystals, M. P. 102, gave a yellow spirit solution. The dye sensitized an unwashed gelatino silver chloride emulsion, the sensitizing maximum being at 440 m and the sensitivity extending to 480 mg with no fog or stain.

Exmm *zQ-s ethyl :2'(3' m'ethyldihydro- 1 :3 '-thiazinylidene-vinyl) -rhodanine CH: (EH1 S OH: lICllCHIC 2 w acetanilidovinyldihydro 1 3 thiazine methiodide (1.52 g.; 1 mol.), 3-ethylrhodanine (0.81 g.; 1 mol.) triethylamine (0.7 c. c.; 1.1 mols.) and absolute alcohol c. 0.) were boiled and stirred together for 4 minutes. The product was washed with water and recrystallized from pyridine. The dull red solid, M. P. 195 C. (decomp.) gave a yellow spirit solution. The dye gave a sensitizing maximum at 545 my and its action extended to 580 my, the ratio of green to blue sensitivity being good. 2-w-acetanilidovinyldihydro-1:3-thiazine methiodide can be prepared according to the general method for preparing acetanilidovinyl cyclammonium quaternary salts set forth in British Patent 344,409, accepted March 4, 1931, viz. by condensing the cyclammonium quaternary salt containing a methyl group (in this case 2-methyl-1z3-thiazine methiodide) with diphenylformamidine, in the presence of acetic anhydride.

Our new dyes are especially useful for sensitizing photographic silver halide emulsions. In the preparation of photographic emulsions containing our new dyes, it is only necessary to disperse the dyes in the emulsions. The methods of incorporating dyes in emulsions aresimple and well known to those skilled in the art. In prac= tice, it is convenient to add the dyes to the emulsions in the form of a solution in an appropriate solvent. Methanol has proved satisfactory as a solvent for our new dyes. The dyes are advantageously incorporated in the washed, finished emulsions.

The concentration of our new dyes in the emulsion can vary widely, e. g. from 5 to about 100 mg. per liter of flowable emulsion. The concentration of the dye will vary according to the type of emulsion and according to the efiects desired. The suitable and most economical concentration for any given emulsion will be apparent to those skilled in the art, upon making the ordinary tests and observations customarily used in the art of emulsion-making. To prepare a gelatino-silverhalide emulsion, the following procedure is satisfactory: A quantity of the dye is dissolved in methyl alcohol or acetone and a volume of this solution (which may be diluted with water) containing from 5 to 100 mg. of dye, is slowly added to about 1000 c. c. of a gelatino-silver-halide emulsion, with stirring. Stirring is continued until the dye is thoroughly incorporated.

With most of our new dyes, about 40 mg. of dye per liter of gelatino-silver halide emulsion suffice to produce the maximum sensitizing effect.

The above statements are only illustrative, as it will be apparent that our dyes can be incorporated in photographic emulsions by any of the other methods customarily employed in the art; as by bathing a plate or film upon which an emulsion is coated, in a solution of the dye in an appropriate solvent, although such a method is not ordinarily to be preferred.

Emulsions sensitized with our new dyes can be coated on to suitable supports, such as glass cellulose derivative film, resin film or paper, in the usual manner.

Our new dyes also give rise to valuable light filters when incorporated in a suitable medium. The medium may be a layer of a colloid such as gelatine or a cellulose derivative or a transparent resin or the like and such layer may be coated on glass or other rigid support. We have found that when incorporated in a colloid medium for the purpose of preparing light filters our new dyes may be used in quantities of about 0.1 gm. to 1 gm. per liter of colloid. If desired, filter layers containing our new dyes may be incorporated in multi-layer photographic elements.

What we claim as our invention and desire to be secured by Letters Patent of the United States is:

1. A merocyanine dye of the following formula:

wherein n represents a positive integer not greater than two, R represents an alkyl group and Z represents the non-metallic atoms necessary to complete a heterocyclic nucleus selected from the group consisting of five-membered and six-membered heterocyclic nuclei.

2. A merocyanine dye of the following formula:

wherein n represents a positive integer not greater than two, R represents an alkyl group and Z represents the non-metallic atoms necessary to complete a five-membered heterocyclic nucleus containing a nuclear sulfur atom and a nuclear nitrogen atom.

3. A merocyanine dye of the following formula:

wherein n represents a positive integer not greater than two, R. represents an alkyl group and Z represents the non-metallic atoms necessary to complete a rhodanine nucleus.

4. A dye of the following formula:

wherein R and R represent alkyl groups.

5. A dye of the following formula:

6. A dye of the following formula:

7. A dye of the following formula:

8. A process for preparing a dye comprising 30 reacting a quaternary salt of a hihydro 1:3- thiazine containing, in the 2-position, a'member selected from the group consisting of alkylthiol groups and w-acylated phenylamino groups, with a heterocyclic compound selected from the group consisting of flve-membered heterocyclic compounds containing a nuclear ketomethylene group and six-membered heterocyclic compounds containing a nuclear ketomethylene group, in the presence of an acid-binding agent.

9. A process for preparing a dye comprising reacting a quaternary salt of a dihydro-1:3- thiazine containing, in the 2-position, a member selected from the group consisting of alkylthiol groups and w-acylatedphenylamino groups, with a rhodanine compound, in the presence of an acid-binding agent.

10. A process for preparing a dye comprising reacting a quaternary salt of a dihydro-1z3- thiazine containing, in the 2-position, an alkylthiol group, with a rhodanine compound, in the presence of an acid-binding agent.

11. A process for preparing a dye comprising reacting a quaternary salt of a dihydro-1t3- thiazine containing, in the 2-position, an wacetanllidovinyl group, with a rhodanine compound, in the presence of an acid-binding agent.

FRANCES MARY HAIVIER. RUSSELL JAMES RATHBONE. 

